Inductive sensors have decisive advantages considering simplicity of implementation, low cost and usability in harsh environments. In this paper, we present a concept of a non-destructive transmissive inductive film thickness sensor for IoT applications. The sensor is based on a transformer principle composed of a fixed sending side using a multi-coil system and one receiving sensor coil. It measures the distance between two objects or the thickness of nonferromagnetic target materials. The sensor coil at the receiving side is battery-less, can be flexibly placed and is connected to a conditioning circuit and a low energy Bluetooth board (STEVAL-IDB007Vl), which starts automatically and sends the sensor output to a smartphone or a tablet. The measurement data are monitored by using a specially developed APP. Experimental results show that the sensor measures film thicknesses up to 1.2 cm with a sensitivity of about 0.032 V/mm and a resolution of 0.3 mm. Thereby a noise level of about 9.6 mV is recorded.
|Titolo:||Non-destructive transmissive inductive thickness sensor for IoT applications|
|Data di pubblicazione:||2018|
|Appare nelle tipologie:||4.1 Contributo in Atti di convegno|